Traditional vehicle dynamics control systems and ride control systems, such as brake systems and suspension systems, for motor vehicles include conventional hydraulically or pneumatically actuated components associated with two or more wheels of the vehicle. Such conventional components are actuated by pressurized fluid or compressed air. In the case of conventional brakes, for example, when actuated, the brakes exert a force on a disk or drum which spins in conjunction with the wheel of the vehicle in order to create frictional forces which resist rotation of the wheel. Traditionally, control signals have been transmitted to each of the vehicle dynamics control system's and/or ride control system's conventional components mechanically, or by a hydraulic or pneumatic control circuit. However, it has more recently been proposed to employ a centralized control unit to generate electronic control signals and to use such electronic control signals to control actuation of system components, such as brake actuators. This type of electronic control scheme has become even more prevalent in view of modern vehicle dynamics control systems and ride control systems which now often include not only conventional hydraulic or pneumatic actuator functionality, but also supplemental electronic functions such as antilock protection (ABS) and/or electronic braking force distribution (EBV) between the front and rear axles.
Such electronic control schemes are generally controlled by one or more electronic control units (ECUs), Which have a program running thereon which receives various inputs and generates electronic control signals which are supplied to each of the vehicle dynamics control system's and/or ride control system's conventional components. However, because of differences between vehicles and/or between requirements imposed by various jurisdictions or vehicle operators, it is often necessary for the ECU to employ vehicle specific parameters in generating the control signals. These vehicle specific parameters are typically initially installed into a configuration data memory of the ECU by a system builder using specialized equipment at the time of manufacture. However, this creates a problem in that if the ECU is subsequently required to be replaced due to failure or damage, the vehicle operator is normally required to re-enter specific system parameter settings into the memory of a replaced and unparameterized ECU.
U.S. Pat. No. 6,447,075 attempts to remedy this problem in the specific context of a vehicle braking system by providing a braking system which includes a braking ECU having an electronically operable control valve which derives suitably proportioned load and vehicle speed dependent service brake pressure for brake chambers of a trailer wheeled. The braking ECU has a data memory storing specific braking parameters normally installed therein prior to commissioning the trailer. The trailer has a further diagnostic ECU responsive to vehicle operational sensors, the further ECU also having memory capacity. The specific braking parameters are stored via a communication link consequent upon installation thereof to the braking ECU. Upon recognizing installation of a replacement braking ECU, the parameters from the diagnostic ECU are installed in the replacement ECU.
While this system does remedy the above-mentioned problem to some degree, it suffers from a number of disadvantages of its own. One such disadvantage arises due to the fact that when the further diagnostic ECU is installed, the braking parameters communicated by the braking ECU are permanently stored in the memory of the further diagnostic ECU. As such, it is impossible for the vehicle operator to modify the stored parameters should his/her requirements and/or the requirements of the jurisdiction in which the vehicle is operated change. For example, if the vehicle were moved from one jurisdiction to another jurisdiction having different requirements, it would be necessary to remove the diagnostic ECU from the system, modify the parameters stored on the braking ECU, and install a new diagnostic. ECU, which would then have the modified parameters from the braking ECU communicated thereto and stored thereon. If the vehicle were moved back to the original jurisdiction, this process would have to be repeated.
What is desired, therefore, is a control system for electronically controlled vehicle dynamics control systems and/or ride control systems which incorporates redundant storage of vehicle control parameters, which includes two memories for separately storing vehicle control parameters, which does not permanently store the vehicle control parameters in either memory, which allows for the vehicle control parameters to be modified, and which, when the vehicle control parameters stored in one of the memories is modified, automatically modifies the vehicle control parameters stored in the other memory.